A 74-year-old Warde Terrace has been charged with sexually assaulting a boy more than a dozen times over a four-year period.

Robert Purcell was arrested Friday on a warrant with first-degree sexual assault and risk of injury to a minor. He turned himself at Police Department headquarters and was given a court-set bond of $100,000. Purcell was scheduled to be arraigned later that same day.

In November, police took Purcell into custody on a Wallingford warrant for the same charges. The victim, a boy, lives in Wallingford and police said the assaults committed by Purcell took place in Wallingford, Fairfield and Stratford.

However, the most serious of the assaults occurred here, police said.

Last October, the boy's parents contacted Wallingford police about the incidents, telling police they believed they knew the suspect and that he lived in Fairfield.

Purcell was interviewed by Wallingford police at Fairfield police headquarters, at which time Detective Beth Irizarry launched the local investigation into the allegations. She determined that Purcell assaulted the boy in February of 2011 in the Warde Terrace home.